....so that even if only a little extra focus is required on a tape, it is too much; cf recent accidents, and
ASAGA.
safetypee,
the eye-tracker data in the referenced ASAGA study deserves comment in light of your comment about 'a little extra focus'.
Firstly, the two ASAGA simulator types (330 & 777) were both tape equipped. How do you derive the above conclusion without a comparison to eye-tracker data obtained in a round dial equipped simulator under the same circumstances.
Secondly, the percentage duration of eye-tracker time centered on airspeed by the PF on GA 1, 2 & 3 respectively were ~12%, 15% & 24%. GA 1 & 2 were hand flown, GA 3 was autopilot flown and one would expect that would allow for more time available to monitor anything and everything.
The average 777 runs were 67 seconds and the average 330 runs were 90 seconds. This equates to 8, 10 & 16 seconds for the T7 and 11, 13, 22 seconds for the 330. Are these times excessive and indicative of 'extra focus'? This is time the eye-tracker is centered on airspeed and not necessarily indicative of 'focus'. (Oh yes, we seem to be missing comparable round dial data)
If Asiana 214 had 'focused' on airspeed for any of these durations during the last 1-1 1/2 minutes of the flight we wouldn't be discussing relative merits of round dials versus tapes....or their apparent eye-tracker score of "0".
FGD135,
Good discussion, but you need to get into 447 threads and find out what that graph is really telling you about the speeds displayed and what you call 'spikes'. Computed Airspeeds are the values sent from the ADRs to the ASIs and NCD is No Computed Data and in that situation the tapes rest on around 46 KIAS (ADRs below 30) just like an electro-mechanical round dial pointer would with no air data input.
But that is "computed" airspeed, not necessarily the same thing that you would see if you were trying to display the pitot-static quantity on a big round dial.
It certainly is if the round dial is ADC fed. Otherwise....
I had pitot icing (rainy overnight and the required pitot system draining wasn't accomplished) in the last airplane I flew without a sophisticated ADC, the F-100. Climbing out of Sacramento, airspeed pointer dropped and pegged at the lower stop, flew pitch and power of course, and on that unusually cold day the nice folks at Nellis scrambled an F-111 to bring me down thru the wx on his wing. Told him to give me 180 KIAS on final and sure enough a little while after we got below the freezing level, the airspeed popped back to 180. If the plumbing gets blocked it doesn't matter whether ASI is fed by ADC or calibrated pitot pressure.
214 & 447 are not good examples to prove your psychophysics fueled point.